The present invention relates generally to sign frames and poster display devices for displaying large signs, posters and other such displays. The invention is particularly advantageous in display frames for large signs and which provide means for accommodating expansion and/or contraction of the sign or poster within the frame, while securely retaining the sign or poster both during mounting and while in service.
Numerous sign frames and poster display devices are used for displaying various signs and messages for advertisement and information to the public. Large signs, especially those made of plastic or synthetic materials can undergo considerable expansion or contraction (e.g., one-half inch or more for every ten feet in length), which can adversely affect the sign's aesthetics and readability, as well as the integrity of the sign panel itself and the sign frame's ability to securely retain the sign. This problem is particularly acute in outdoor displays, highlighted or backlighted displays, and in mobile displays, or where signs are otherwise exposed to significant wind forces. Therefore, one of the primary purposes of the present invention is to provide a sign frame and poster display device for large sign applications in which the sign, poster or other display is exposed to temperature, weather, or other environmental conditions which tend to alter its shape.
One recent example of a display device that successfully addresses the problems discussed above is described in U.S. Pat. No. 4,580,361, which is assigned to the same assignee as the present invention, and the disclosure of which is hereby incorporated by reference. Although this display device has proved to be superior to those of the prior art, it has been found that the present invention provides even further improvements in the display's ability to securely retain large and unwieldy sign or poster panels during installation in the display frame, as well as after installation when subjected to high external loads such as high winds.
In accordance with the present invention, a preferred sign frame and poster display device holds the sign or poster securely on all edges and allows for expansion and contraction of the sign. The sign frame and poster display device can be of virtually any length or width and preferably includes a plurality of elongated frame sections, each having a base member and a hinged cover member pivoted together along their outside edges and preferably resiliently biased toward their open or closed positions in an over-center force arrangement such as that described in the above-mentioned U.S. Pat. No. 4,580,361. At least one slide member is resiliently mounted inside the base member in this embodiment of the invention and is adapted for movement in any direction in a plane parallel to the sign and poster surface. Each of the slide members includes a post or peg adapted to be received within a corresponding aperture near the perimeter of the poster or sign panel. Preferably, a retainer member is pivotally interconnected with a portion of the slide member for movement into and out of interlocking engagement with the peg or post after the poster or sign panel has been installed thereon. Such interlocking engagement of the retainer member with the peg or post greatly reinforces and increases the strength of the peg or post and to securely retain the poster or sign panel in place during installation, which significantly aids in the handling and installation of large or unwieldy posters or signs. After the poster or sign panel has been properly positioned along all of its edges, the hinged cover member is pivoted to its closed position, and the retainer members remain in their interlocking engagement with the corresponding slide members to reinforce the peg or post and to securely retain the poster or sign panel while the display assembly is in service. The retention arrangement of the present invention is also equally applicable to display devices having stationary poster or sign mounting apparatus in lieu of the above-discussed movable slide members, as well as to display devices other than the type described above.
Further objects, features and advantages of the present invention will become apparent from a review of the drawings when read in accordance with the accompanying specification.